The invention relates to a non-steroidal compound with affinity for estrogen receptors and to a method for selective estrogen receptor modulation (SERM) with such a compound and to the use of such a compound for the manufacture of a medicine for estrogen-receptor-related treatments.
Compounds with affinity for estrogen receptors have found long-standing utility in the treatment of a variety of medical indications and in regimes for contraceptive purposes. Despite the long history of the field there still is a need for more effective, safer and more economical compounds than the existing ones. This need is the more pressing in view of advancement in health care in other areas, which has led to an increasingly longer life span. This is in particular a problem for women for whom the decline in estrogenic hormones at menopause is drastic and has negative consequences for bone strength and cardiovascular functions. For the control or prevention of estrogen sensitive tumor growth, compounds are needed which are antagonists, partial antagonists or tissue selective agonists for estrogen receptors.
The discovery of subtypes of estrogen receptors, there being an xcex1-subtype (ERxcex1) and a xcex2-subtype (ERxcex2) of such receptors (Mosselman et al., FEBS Letters vol. 392 (1996) pp. 49-53 as well as EP-A-0 798 378), offers the possibility to influence one particular subtype of those two receptors more selectively, immanently resulting in more effective treatments or treatments with less side effects. Since these receptors have a different distribution in human tissue, the finding of compounds which possess a selective afinity for either of the two is an important technical progress, making it possible to provide a more selective treatment in estrogen-receptor related medical treatments, such as those for contraception and for treatment of menopausal complaints, osteoporosis, and estrogen dependent tumour control, with a lower burden of estrogen-related side-effects.
This invention pertains to non-steroidal estrogenic compounds with a 10-aryl-11H-benzo[b]fluorene or a 7-aryl-5,6-dihydrobenz[a]anthracene skeleton. Compounds with a 10-phenyl-11H-benzo[b]fluorene skeleton are described as products from enediyne thermocyclisation [Schittel, M., Z. Naturforsch, B: Chem. Sci. (1998), 53, 1015-1020] and from [4+2] cycloaddition reactions of diarylacetylenes [Rodriguez, D., Org. Lett. (2000), 2, 1497-1500], but no medicinal activity of these compounds is known. Indeno[1,2-g]quinolines with interactions with nuclear receptors are disclosed in WO 96 19458. Despite the keen interest in compounds with affinity for the estrogen receptor, new compounds with a 10-aryl-11H-benzo[b]fluorene or 7-aryl-5,6-dihydrobenz[a]anthracene skeleton and affinity for the estrogen receptor cannot be learnt from these documents.
The present invention resides in the finding that compounds with an unsaturated or partially unsaturated four-ring skeleton with hydroxyl substitutions at specific locations, i.e. 2,8-dihydroxy-10-aryl-11H-benzo[b]fluorene and 3,9-dihydroxy-7-aryl-5,6-dihydro-benz[a]anthracene, possess surprisingly high antagonism for ERxcex2. Some of these compounds also show ERxcex1 antagonism or ERxcex1 agonism.
Specifically, the invention provides non-steroidal compounds having the formula 1
wherein:
Re and xe2x80x2Re are OH, optionally independently etherified or esterified;
Z is xe2x80x94CH2xe2x80x94 or xe2x80x94CH2CH2xe2x80x94;
R1 is H, halogen, CF3, or (1C-4C)alkyl;
R2, R3 and R4 are independently H, halogen, xe2x80x94CF3, xe2x80x94OCF3, (1C-8C)Alkyl, hydroxy, (1C-8C)alkyloxy, aryloxy, aryl(1C-8C)alkyl, halo(1C-8C)alkyl, xe2x80x94O(CH2)mX, wherein X is halogen or phenyl and m=2-4; xe2x80x94O(CH2)mNRaRb, xe2x80x94S(CH2)mNaRb or xe2x80x94(CH2)mNRaRb, wherein m=2-4 and wherein Ra, Rb are independently (1C-8C)alkyl, (2C-8C)alkenyl, (2C-8C)alkynyl, or aryl, optionally substituted with halogen, xe2x80x94CF3, xe2x80x94OCF3, xe2x80x94CN, xe2x80x94NO2, xe2x80x94OH, (1C-8C)alkoxy, aryloxy, carboxyl, (1C-8C)alkylthio, carboxylate, (1C-8C)alkyl, aryl, aryl(1C-8C)alkyl, halo(1C-8C)alkyl or Ra and Rb form a 3-8 membered ring structure, optionally substituted with halogen, xe2x80x94CF3, xe2x80x94OCF3, xe2x80x94CN, xe2x80x94NO2, hydroxy, hydroxy(1C-4C)alkyl, (1C-8C)alkoxy, aryloxy, (1C-8C)alkylthio, carboxyl, carboxylate, (1C-8C)alkyl, aryl, aryl(1C-10 8C)alkyl, halo(1C-8C)alkyl.
Preferred compounds of the invention can be obtained by selecting xe2x80x94CH2xe2x80x94 for Z and hydrogen for R4 in formula 1. For R1 it is preferred to select compounds having H, halogen or CF3. Compounds with R1 in formula 1 is halogen, whereby chlorine is most preferred, are particularly potent and selective for the ERxcex2.
Another embodiment of the invention is a non-steroidal compound with a 10-Aryl-11H-benzo[b]fluorene skeleton having the formula 2 
wherein:
Re and xe2x80x2Re are OH, optionally independently etherified or esterified;
R1 is H, halogen or CF3;
R2 and R3 are independently H, halogen, xe2x80x94CF3, xe2x80x94OCF3, (1C-8C)Alkyl, hydroxy, (1C-8C)alkyloxy, aryloxy, aryl(1C-8C)alkyl, halo(1C-8C)alkyl, xe2x80x94O(CH2)mNRaRb, xe2x80x94S(CH2)mNRaRb or xe2x80x94(CH2)mNRaRb, wherein m=2-4 and Ra, Rb are independently (1C-8C)allyl, (2C-8C)alkenyl, (2C-8C)alkynyl, or aryl, optionally substituted with halogen, xe2x80x94CF3, xe2x80x94OCF3, xe2x80x94CN, xe2x80x94NO2, xe2x80x94OH, (1C-8C)alkoxy, aryloxy, carboxyl, (1C-8C)alkylthio, carboxylate, (1C-8C)alkyl, aryl, aryl(1C-8C)alkyl, halo(1C-8C)alkyl or Ra and Rb form a 3-8 membered ring structure, optionally substituted with halogen, xe2x80x94CF3, xe2x80x94OCF3, xe2x80x94CN, xe2x80x94NO2, hydroxy, (1C-8C)alkoxy, aryloxy, (1C-8C)alkylthio, carboxyl, carboxylate, (1C-8C)alkyl, aryl, aryl(1C-8C)alkyl, halo(1C-8C)alkyl.
For compounds, having formula 3, 
it is preferred to select those in which
Re and xe2x80x2Re are OH, optionally independently etherified or esterified;
R1 is H, halogen, CF3;
R2 is xe2x80x94O(CH2)mNRaRb, wherein m=2-3 and Ra, Rb are independently (1C-5C)alkyl or (3C-5C)alkenyl, optionally substituted with OH or methoxy, or Ra and Rb form a 4-7 membered ring structure selected from the list: azetidine, pyrrolidine, 3-pyrroline, piperidine, piperazine, tetrahydropyridine, morpholine, thiomorpholine, thiazolidine, homopiperidine, tetrahydroquinoline and 6-azabicyclo[3.2.1]octane, which 4-7 membered ring structure can optionally be substituted with OH, methoxy, acetyl, carboxylate, (1C-3C)alkyl, phenyl, benzyl, and phenylethyl.
In particular, a very effective compound is made available by this invention by selecting a compound having formula 4: 
wherein:
Re and xe2x80x2Re are OH, optionally independently etherified or esterified;
R2 is (3C-6C)alkyloxy, xe2x80x94O(CH2)mX (wherein X is halogen or phenyl and m=2-3), or xe2x80x94O(CH2)mNRaRb, (wherein m=2-3), whereby Ra, Rb are independently (1C-5C)alkyl or (3C-5C)alkenyl, optionally substituted with OH or methoxy, or Ra and Rb form a 4-7 membered ring structure selected from the list: azetidine, pyrrolidine, 3-pyrroline, piperidine, piperazine, tetrahydropyridine, morpholine, thiomorpholine, thiazolidine, homopiperidine, tetrahydroquinoline and 6azabicyclo[3.2.1]octane, which 4-7 membered ring structure can optionally be substituted with OH, hydroxy(1C-2C)alkyl, methoxy, acetyl, carboxylate, (1C-3C)alkyl, phenyl, benzyl, and phenylethyl.
In those cases that the compound in formulas 1-4 contain a basic amine function, the compound may be used as a free base or as a pharmaceutically acceptable salt such as hydrochloride, acetate, oxalate, tartrate, citrate, phosphate, maleate or fumarate.
The ester and ether compounds in the collection of compounds according to the invention often have activity as prodrug. A prodrug is defined as being a compound which converts in the body of a recipient to a compound as defined by the formulas 1 to 4 and to the free hydroxyl compounds of the above defined compounds. Preferred ester and ether prodrugs are carboxylic acid esters or alkyl ethers on one or both hydroxyl groups, and more preferred prodrugs are (2C-6C)carboxylic acid esters, such as esters of (iso)butanoic acid, or (1C-4C) alkyl ethers. In general, the hydroxy groups can for example be substituted by allyl*oxy, alkenyl*oxy, acyl*oxy, aroyloxy, alk*oxycarbonyloxy, sulfonyl groups or phosphate groups, whereby the carbon chain length of the groups denoted with an asterisk (*) is not considered to be sharply. delimited, while aroyl generally will comprise a phenyl, pyridinyl or pyrimidyl, which groups can have substitutions customary in the art, such as allyl*oxy, hydroxy, halogen, nitro, cyano, and (mono-, or dialkyl*-)amino. The length of the alkyl, alkenyl and acyl groups is selected depending on the desired properties of the prodrugs, whereby the longer chained prodrugs with for example lauryl or caproyl chains are more suitable for sustained release and depot preparations. It is known that such substituents spontaneously hydrolyse or are enzymatically hydrolysed to the free hydroxyl substituents on the skeleton of the compound. Such prodrugs will have biological activity comparable to the compounds to which they are converted in the body of the recipients. The active compound to which a prodrug is converted is called the parent compound. The onset of action and duration of action as well as the distribution in the body of a prodrug may differ from such properties of the parent compound.
Substitution variants of the compounds of the present invention are possible for similar use. A substitution variant is defined to be a compound which comprises in its molecular structure the structure as defined by the formula I. The skilled person inspecting the group of compounds provided by the present invention will immediately understand that modification by a substituent to the skeleton can yield a compound with similar biological activity as the compound without this particular substituent. It is common practise in the art to test such substitution variants for the expected biological activity so that it is a routine skill to obtain useful substitution variants of compounds according to the invention.
Other terms used in this description have the following meaning:
alkyl is a branched or unbranched alkyl group, for example methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, hexyl, octyl, capryl, or lauryl;
alkenyl is a branched or unbranched alkenyl group, such as ethenyl, 2-butenyl, etc.;
alkynyl is a branched or unbranched alkynyl group, such as ethynyl and propynyl;
halogen refers to fluorine, chlorine, bromine and iodine;
aryl is a mono- or polycyclic, homo- or heterocyclic aromatic ring system, such as phenyl, naphtyl or pyridinyl; a monocyclic ring with 6 atoms is preferred for use;
a ring system or structure is referring to a chemical group in which all atoms are involved in formed rings, which rings can be saturated or (partially) unsaturated and comprise C, O, S or N atoms;
aroyl is arylcarbonyl such as a benzoyl group;
alkanoyl means a formyl or alkylcarbonyl group such as formyl, acetyl and propanoyl;
acyl is a (substituent-)carbonyl group, such as an aroyl or alkanoyl;
carboxyl is a xe2x80x94COOH substituent, making the compond an organic acid; carboxylate is an ester or salt of a carboxyl substituent.
The prefixes (1C-4C), (2C-4C) etc. have the usual meaning to restrict the meaning of the indicated group to those with 1 to 4, 2 to 4 etc. carbon atoms.
The estrogen-receptor affinity profile of the compounds according to the present invention, makes them suitable for use in estrogen-receptor related medical treatments, in the sense that these compounds are improved anti-estrogens, partial anti-estrogen, partial estrogens or selective (partial) (anti-)estrogens. Estrogen-receptor related medical treatments specifically named are those for contraception or for treatment or prevention of benign prostate hypertrophy, cardiovascular disorders, menopausal complaints, osteoporosis, estrogen dependent tumour control or central nervous system disorders such as depression or Alzheimer""s disease. In particular those compounds which have selective affinity for the ERxcex2 receptor are suitable for estrogen-receptor related medical treatments under diminished estrogen-related side-effects. This is most desirable when these compounds are used in the treatment of osteoporosis, cardiovascular disorders and central nervous system disorders such as depression or Alzheimer""s disease. Selective blockade of ERxcex2-receptors with compounds of this invention can be used to prevent and reduce malignent tumor growth and hyperplasias. The receptor selectivity helps to effectuate tissue selectivity. Those tissues rich in ERxcex2-receptors can be protected by ERxcex2-receptor antagonists from the risk of stimulation of growth by estrogenic agonists. The latter can be of endogenous origin or from exogenous origine when administered during estrogenic treatment, for example for hormone replacement after menopause. Tissues that can benefit from protection in view of the presence of ERxcex2-receptors are prostate, testes (human), lung, colon and endometrium. In particular, endometrium proliferation can be reduced by ERxcex2 antagonists of the invention.
The compounds of the invention can be produced by various methods known in the art of organic chemistry in general. More specifically the routes of synthesis as illustrated in the schemes and examples can be used. 
occasionally accompanied by other substituents 
With reference to scheme 1, the benzofluorene (Z=CH2) and the benzanthracene (Z=CH2CH2) skeleton can be assembled in an identical manner. In step A adequately substituted indanones or tetralones are treated with CS2 under appropriate basic conditions to introduce a dithioketene function (in fact serving as a carboxylate equivalent), after which procedure reaction with an organometallic derivative of a substituted benzylhalide (preferably a Grignard derivative) in step B, followed by alcoholysis (step C) leads to an xcex1,xcex2-unsaturated ester. At this stage an acid catalyzed cyclization (step D) immediately leads to the phenolic benzofluorene (or benzanthracene). Conversion of this into a reactive intermediate (like triflate) in step E allows the introduction of the desired functionalities (like aryl groups, carboxylates etc) by means of known organometallic techniques.
If the mentioned xcex1,xcex2-unsaturated ester is first hydrogenated in step F prior to cyclization (step G), the indicated ketones become available. They may be easily converted into the aromatic iodide in step H. These, under circumstances may be more reactive than the afore-mentioned triflates and provide valuable alternatives for finctionalization (step I in scheme 2).
Ester prodrugs can be made by esterification of compounds with free hydroxyl groups by reaction with appropriate acyl chlorides in pyridine. Free dihydroxy compounds having formula 1 can be made by hydrolysis of ether precursors.
The present invention also relates to a pharmaceutical composition comprising the non-steroidal compound according to the invention mixed with a pharmaceutically acceptable auxiliary, such as described in the standard reference Gennaro et al, Remmington: The Science and Practice of Pharmacy, (20th ed., Lippincott Williams and Wilkins, 2000, see especially Part 5: Pharmaceutical Manufacturing). Suitable auxiliaries are made available in e.g. the Handbook of Pharmaceutical Excipients (2nd Edition, Editors A. Wade and P. J. Weller; American Pharmaceutical Association; Washington; The Pharmaceutical Press; London, 1994). The mixture of the compounds according to the invention and the pharmaceutically acceptable auxiliary may be compressed into solid dosage units, such as pills, tablets, or be processed into capsules or suppositories. By means of pharmaceutically suitable liquids the compounds can also be applied as an injection preparation in the form of a solution, suspension, emulsion, or as a spray, e.g. nasal spray. For making dosage units, e.g. tablets, the use of conventional additives such as fillers, colorants, polymeric binders and the like is contemplated. In general any pharmaceutically acceptable additive which does not interfere with the function of the active compounds can be used. The compounds of the invention may also be included in an implant, a vaginal ring, a patch, a gel, and any other preparation for sustained release.
Suitable carriers with which the compositions can be administered include lactose, starch, cellulose derivatives and the like, or mixtures thereof used in suitable amounts.
Furthermore, the invention relates to the use of the non-steroidal compound according to the invention for the manufacture of a medicament for estrogen-receptor related treatments and treatment of estrogen-receptor related disorders such as peri- and/or post-menopausal complaints. Thus the invention also pertains to the medical indications of peri- and/or post-menopausal (climacteric) complaints and osteoporosis, i.e. a method of treatment in the field of hormone replacement therapy (HRT), comprising the administration to a patient, being a woman, of a compound as described hereinbefore (in a suitable pharmaceutical dosage form).
Further, the invention relates to the use of the non-steroidal compound according to the invention in the manufacture of a medicament having contraceptive activity. Thus the invention also pertains to the medical indication of contraception, i.e. a method of contraception comprising the administration to a subject, being a woman or a female animal, of a progestogen and an estrogen as is customary in the field, wherein the estrogen is a compound as described hereinbefore (in a suitable pharmaceutical dosage form).
Finally the invention relates to the use of the non-steroidal compound for the manufacture of a medicament having selective estrogenic and/or anti-estrogenic activity, such a medicament being generally suitable in the area of HRT (hormone replacement therapy).
The dosage amounts of the present compounds will be of the normal order for estrogenic compounds, e.g. of the order of 0.01 to 100 mg per administration.
The invention is further illustrated hereinafter with reference to some unlimitative examples and the corresponding formula schemes referred to. Compounds are identified by numbers (in bold letter type) with reference to the corresponding numbers in the schemes. Abbreviations used in the schemes: Me is methyl, Bn is benzyl, ph is phenyl, aryl represents the substituted phenyl as in formula 1.